This invention concerns a pyrotechnic slapper-detonator with coaxial connections.
Such detonators, also known as EFIs ("Exploding Foil Initiators"), can be used in particular to initiate warheads or propellers of rockets, missiles or all guided projectiles, or gas generators (in the latter case the initiators are known as igniters).
In the field of detonation, i.e. explosives, solid warheads can be initiated, for example, by a violent projection of material on to an intermediate charge causing the initiation of this charge. This projection is produced by an explosion of a vaporizable metal film, this explosion being generally obtained by two different processes:
either by passing an electric current pulse,
or by absorption of a pulse of light generated by a laser.
The present invention concerns in particular the first of these methods: the material to be projected is placed on the conducting element. To trigger the device an electrical discharge of very short duration but high intensity is passed through this element. The material is then projected against the intermediate charge, its kinetic energy causes initiation of this charge.
One embodiment of this type of detonator, described in French patent application No. 87 08813, filed on Jun. 23 1987, includes an electrical element comprising two strands connected at their ends and placed sufficiently close to each other to constitute a conductor of low inductance. This electrical element penetrates the wall of the device at least one point to be able to connect it to an external electrical supply. This flat connector is difficult to fabricate and is fragile. Moreover the construction of such a system involves problems of integration, size and gas-tightness. Another category of detonator, described in the same patent application, includes an electrical element whose electrical supply is via two electrodes perpendicular to the element. In this system the size of the device, although smaller than the first embodiment, is still large. There also remain problems of gas-tightness in this system which can result in deterioration, for example corrosion of the electric element.
To remedy these problems, the Applicant proposed in French patent application No. 89 07675, filed on Jun. 9, 1989, a pyrotechnic slapper-detonator or initiator including coaxial connections. Such a system has many advantages, in particular as regards the gas-tightness of the electric element (allowing prolonged storage), rigid construction, very simple assembly and relatively low cost. Such a detonator remedies the problems mentioned earlier.